Optical Characterization and Analysis of Disordered Materials Based on Hollow Silicon Dioxide Microparticles for Passive Daytime Radiative Cooling

Passive daytime radiative cooling (PDRC) is an innovative sustainable technique that utilizes the principles of thermal radiation to achieve cooling without active energy consumption. PDRC exploits high reflectance of solar radiation and strong emission of longwave infrared thermal radiation through the atmospheric window (8-13 µm), allowing the creation and design of surfaces able to achieve sub-ambient temperatures by passively dissipating excess heat into the cold sky, even under daylight conditions. This thesis investigates the optical properties and thermal performances of potential PRC materials, focusing on disordered materials composed of hollow silicon dioxide (SiO₂) microparticles. The unique morphology of hollow SiO₂ microparticles provides peculiar scattering and emissivity characteristics, making them ideal candidates for enhancing PDRC efficiency. This research links material science, optics, and sustainability, offering an interesting and promising future for energy-efficient cooling solutions.